Autocomplete Plugin - Passing in a Checkbox Value

Autocomplete Plugin - Passing in a Checkbox Value

I'm using the autocomplete plugin from this tutorial:
http://viralpatel.net/blogs/2009/06/tutorial-create-autocomplete-feature-with-java-jsp-jquery.html
Environment is Windows XP 5.1.2600, Firefox 3.6.8 and Chrome 5.0.375

Code Snippets:
    <input type="text" id="country" name="country"/>
    <input type="checkbox" name="mycheck" id="mycheck" />

<script>

        $("#mycheck").click(function() {
            alert($('input[name=mycheck]:checked').val());
        });

        $("#country").autocomplete(
                "getdata.jsp",{
                    cacheLength:0,
                    minChars:1,
                    max:10,
                    autoFill:false,
                    extraParams: {
                        mycheck: function() { return $('input[name=mycheck]:checked').val(); }
                    }
                });
    </script>

getdata.jsp looks like:
      <%
          DummyDB db = new DummyDB();
          String query = request.getParameter("q");
          List<String> countries = db.getData(query);
          Iterator<String> iterator = countries.iterator();
          while (iterator.hasNext()) {
              String country = (String) iterator.next();
              out.println(country);
          }
      %>

If I use this line in getdata.jsp:
      String param= request.getParameter("mycheck");
The value I get back is:
      function() { return $('input[name=mycheck]:checked').val();     

If I change my extraParams to this:
                  extraParams: {
                        mycheck: function() { return 'hello, world!' }
                    }
The value I get back is:
      function() { return 'hello, world!' }

It seems to interpret the function as a static value, and doesn't actually execute it.  Of course, I can't just simply use this:
             extraParams: {    
                        mycheck: $('input[name=mycheck]:checked').val();
                    }
as the AutoComplete plugin always returned it’s initial value.  I've found quite a few helpful links online about this, notable this one:
      http://blog.qumsieh.ca/2009/09/08/jquery-autocomplete-extraparams-and-checkboxes/

Hence the above code using a function which I posted, but can't get that to work.  Any help or hints would be helpful.  Thanks in advance!